The Microcontroller And Its Support Circuits; The E-500Txn Microcontroller; Fig. 2.8 The E-500Txn Microcontroller; Tab. 2.1 Description Of The E-500Txn Microcontroller Signals - ELCOM Euro-500 Handy Series Service Manual

Euro-500TX Handy
VRAM power supply for the microprocessor, RAM memory, and the real-time circuit
values: 4.75 V ± 5 %
VCC1 power supply for the logical circuits (the group of logical circuits powered only in normal
mode)
values: 4.9 ± 5 %
VH power supply for the printer performance circuits, the step-motor, the circuit producing the
FM programming voltage, and the drawer opening circuit
values: 24 V ± 0.2 V while mains powered
VFP the fiscal memory programming voltage
values: from 12.5 V to 13 V
VFD the fiscal memory programming voltage
values: from 6 V to 6.5 V
VBAT1 accumulator voltage
values: from 5.5 V (accumulator empty) to 9.25 V (accumulator full), standard operating
voltage from 7.2 V to 8.2 V

2.2 The microcontroller and its support circuits

2.2.1 The E-500TXN microcontroller

The ECR Euro-500TX Handy employs the 16-bit microcontroller E-500TXN. This microcontroller fully con-
trols the ECR. Its properties are:
• 2 kB RAM on chip
• 11 I/O ports
• maximum 16 MB of ad-
dressing for the programme
memory
• maximum 16 MB of ad-
dressing for the data memo-
ry
• five 16-bit timer/readers
• seven external interrupts
• two full duplex serial chan-
nels (USART)
• 10-bit A/D converter, eight
channels
• 8-bit D/A converter,
channels
• watchdog timer
• clock frequency
18 MHz
• on-chip oscillator and timer
circuits
• QFP 100 case
The figure 2.8 shows the pin place-
ment and the table 2.1 lists the pin
descriptions for the E-500TXN.
Pin #. Signature
1 VRAMx
2 FM-AL/CN0
3 FM-AH/CN1
4 A16/CN2
5 FM-DIR/SCL
6 SDA

Tab. 2.1 Description of the E-500TXN microcontroller signals

Service manual
23 V ± 0.3 V while accumulator powered
1
VRAMx
2
FM-AL/CN0
3
FM-AH/CN1
4
A16/CN2
5
FM-DIR/SCL
6
SDA
7
FM-SEL
8
FM-PGM
9
VPP-GEN
10
NC
11
GND
12
TXD0
13
TXD1
14
RXD0
15
RXD1
two
16
EKB-DAT
17
EKB-CLK
18
FD0
19
FD1
20
up to
FD2/RW2
21
FD3/RW3
22
GND
23
FD4/RW4
24
FD5/JP4
25
FD6/JP5

Fig. 2.8 The E-500TXN microcontroller

Type Signal description
I +5V power supply
O validity of lower address byte for FM / keyboard control
O validity of higher address byte for FM / keyboard control
O highest address bit for FM / keyboard control
O permission to read data from FM / clock signal for serial EPROM
I/O data conductor for communication with serial EPROM
E-500TXN
© Elcom, s. r. o.
75
MD2
74
MD1
73
MD0
72
NC
71
HWR
70
RD
69
NC
68
VRAMx
67
XTAL
66
EXTAL
65
GND
64
NMI
63
RST
62
STBY
61
SYSCLK
60
LCD-DATA
59
LCD-CLK
58
LCD-SEL
57
GND
56
NC
55
A18
54
A17
53
A16
52
A15
51
A14
13